Centrifugal hammer



CENTRIFUGAL HAMMER Filed Aug. 19, 1926 4 Sheets-Sheet 2 llll l if 27` Fig@ M Fig. n

n S l I 77, @0,57 e virch June: 30, 1931.

N. GEoRGEvx-rcl-l 1,812,692

CENTRIFUGAL HAMMER Filed Aug. 19, 1926 4 Sheets-Sheet 3 June 3o, 1931. y

N. GERGl-:vrrcl-l CENTRIFUGAL HAMMER Filed Aug. 19, 1926 4 Sheets-fSheet 4 'Patented' June 30, 1931 UNITED STATES NICOLAS GEORGEVITCH,F PARIS,

CENTRIUGAI. HAMMER rRANcE, AssmNoR 'ro Josera ALFREDDAHME, or PARIS, FRANCE Application leil August 19, 1926, Serial No. 130,312, and in France August 25, 192.5.

plify and cheapen the cost of manufacture and facilitate their manipulation in practice. Theinvention consists in acentrifugal hammer of the kind referred to characterized by the featurev thata rolling member is employed as theimpact device.

n' hammer Aor the kind referred to characterized by thefeature that a-reely movable ball vis .employed as the impact device.

The invention also consists in a centrifugal hammer ef ure kind referred te in whieh ure cam and rolling track upon which the impact member travels during rotation are formed integral or in one piece.

. The invention -furthery consists in acentriugal hammer according to the preceding paragraph in which the member forming the rolling 'track and cam presents internally a rolling surface of curvilinear form which comprises a part concentric withthe axis o rotation of the hammer anda part 'of spiral or other like form* leading to the cutaway part `of the cam which permits of the sudden release of the impact device.v

The invention also consists in a centrifugal 40 hammer of the kind referred to in which the impact device isfreely movable in a sleeve or socket adapted to be rotated` by sultable means. l

The invention also consists in other details and arrangements hereinafter described or indicated. A

The accompanying drawings illustrate two modes of carrying out the invention.v

Figure 1 is a.- longitudinal sectional ele- 5 vation of one form of hammer in accordance The invention also conslsts m a centrifugal with the invention, the parts being shown in position at the moment of. impact.

Figure 2 is a section on the line II-I oi'i Figure 1, the parts being shown however in theposition occupied immediately before the release of the impact device by the cam.

Figure 3 is a longitudinal sectional ele-l vation of `one form of driving device which -may be combined with the hammer,'and

' Figure 4 is an outside. elevation of the complete `device showing the hammer and the driving device united together.

Figure 5 is a. longitudinal sectional ele-4 vation showing a second form of centrifugal hammer in accordance with the invention, the

impact member being shown as just leavingthecam. eV-Figure 6 isa similar view to Figure 1 but "showing the position of the parts at the moment of impact.

Figure 7 is a side elevation of the device, and

Figure 8 is a sectional -plan taken upon the line V-'V in Figure 3. l

. In carrying my invention .into effect in one convenient manner as shown in Figures 1 to 4, I form the impact device asa rolling mass, 1, which in the construction illustrated takes the form-of aball but which may also be a-roller or any member adapted to be dis-- placed by rolling. A

i The ball, 1, is freely movable longitudinally'in a driving socket or sleeve, 2, the longitudinal 'dimensions of which are so .chosen that duringv rotation the sleeve orv socket will n'ot come in'to contact with the rolling track, 3, or the' cam, 4, which is integr'al therewitl1,bl1t in order to allow the eX- tent of drop of theilnpact mass from the end of the cam to be as much as possible without soY at ythe same time unduly increasing the di- 1 'ameter of the hammer, the sleeve or socket is provided with a slot or opening, 5, which more or less frames or straddles the rolling track and cam during rotation.

According to the purpose for. which the apparatus is to be employed and for any given type according to the over-all diameter of the same and the dimensions of the impact mass, the notch or slot, 5, may be of greater or less depth and in some cases may be dispensed with altogether..

The driving socket or sleeve, 2, is provided with two trunnions, 6 and 7, mounted respectively in ball bearings, 8 and 9, the trunnion, 6, being solid and having keyed thereon the pinion, 10, which engages the bevel pinion, 11, secured to the shaft of the motor or other prime mover by which the hammer is rotated while the trunnion, 7, is hollow and is closed at its end by the removable plug, 12. The cavity, 13, thus formed in the trunnion acts as an oil reservoir and there is located therein a wick, 22, of which the ends are flush with the inner wall of the socket, 2, the ar# rangement being such thatif the cavity, 13, is filled with oil (conveniently through a lateral orificeV normally closed by the screw 23) the lubrication of the socket and the rolling mass is obtained during the operation of the apparatus due to the wiping by the wick of the rolling mass during the backward and forward movement of such mass in the socket.

The rolling track, 3, and the cam, 4, are formed integral with one another in a single piece which is provided at its lower part with an aperture or slot for the passage therethrough of the anvil, mandril, or tool-holder, 14, with which the machine is provided.

The internal curvature of the rolling track may vary according to the type of apparatus and the height of drop which it is desired to give to the rolling mass and may for example, comprise a circular part concentric with the axis of the guide and a part of spiral shape leading to the point of release of the impact device.

In the example shown in Figure 2 of the drawings the spiral part of the curve extends over an angle of 1800 but the magnitude of this angle may be varied according to the purpose for which the apparatus is required and it is also possible as regards the nature of the curves themselves to choose the same according to tue desired height ol drop of the impact device and the conditions of use provided for the hammer.

In operation the hammer is rotated rapidly by any suitable means and the rolling mass, 1, moves outwards under the action of centrifugal for-ce so that it runs upon the rolling track, 3, and the cam forces the rolling mass radially inwards against the centrifugal force until it reaches the end, 15, of the cam when the impact device is suddenly released to strike a blow upon the anvil or like member, 14, which transmits to the tool the blows received fromthe impact device. The movement of the anvil may be damped or cushioned on the one hand by a washer, 16, placed between the `flange, 17, and the shoulder, 18,

-of thev casing and on the other hand by a large number of washers, 19, formed of fibre, metal, or other suitable material and clamped between the flange, 17, of the anvil and the flange, 20, of the tool-carrying member, 2l. The washer, 16, opposes tightening or drawing together of the shoulder, 18, whiclrlf allowed to take place would cause a bindmg of the anvil in the casing and, moreover, the arrangement of the washers, 16 and 19, also deadens the vibrations produced by the blow ofthe impact member an d which would otherwise be prejudicial to the safety of the apparatus.

In the drawings the anvil, 14, is shown independent of the tool-carrying member, 21, but in some cases these two parts may be formed in one with one another in which case the damping device may be as above described or may be replaced by any other shock-absorbing or restraining means.

In the form of apparatus illustrated the movement of the apparatus is controlled by l an electric high speed motor, 24, upon the shaft ol* which is keyed the bevel pinion, 11, engaging the bevel wheel, 10, the diameters of the respective gears being chosen according tothe speed of the motor so as to give the socket the desired angular velocity, it being understood that such gears may be replaced by a friction or any other suitable power transmission mechanism.

The motor may conveniently be arranged in the casing, 25, and as shown in Figure 4 may be directly secured upon the casing, 26, of the hammer mechanism by means, for eX- ample, of the bolts, 27. The casing, 25, may be provided with a grip for holding the apparatus and upon this grip may be disposed a switch, 28, for starting and stopping the motor.

In the modification of the invention shown in Figures 5 to 8, the centrifugal hammer comprises a casing, 29, of cylindrical form in the interior of which is rotatably mounted a fly-wheel, 30, carried by the shaft, 31, and adapted to be actuated by an electric motor or any other suitable form of mover.

In the particular construction illustrated the fiy-wheel is formed of two similar partsl so constructed that when they are fitted together and assembled by means of bolts there is a dialnetral cavity formed between said parts of cylindrical form but conveniently having one end slightly closed in order to retain within such cavity the ball or other rolling member, 32, which constitutes the impact device.

Upon that side of the shaft, 32, remote from the ball the cylindrical cavity carries a weight, 34, held in place by the flange, 35.l engaging in a corresponding groove, the object of such counterweight being to balance the weight of the ball, 32, during the rotation of the fly-wheel.

The projecting parts of the fly-wheel adjacent to the ends of the cylindrical cavity are so formed as to produce grooves or channels, 35, therebetween so that the ily-wheel will not durin its rotation touch the cam, 36, or the top o the punch or mandril, 37 the arrangement being such that it allows of a greater extent of drop for the impact member without increasing the over-al1 diameter of the {1y-wheel.

i At the lower part of the casing, 29, there 1s secured by suitable means a sleeve or casing, 38, in which is mounted the tool-carrying punch or mandril, 37, which receives the blows of' the impact member, the punch .or mandril bein adapted to slide in the sleeve or casing an being guided in part by the walls of the latter and in part by the aperture formed in the body of the casing through whlch such punch or mandril passes.

i A set of springs, 39, held between the closlng member, 40, and the lower part of the 'punch or mandril serves to return the latter into its original position after the blowhas been received. Y

It may' happen that'in consequence of wear upon the springs, 39, or as the result -of an accident of some kind the mandril may bemoved into such a position that the impact member, 32, cannot come into contact therewith in which casethere is a danger of the {1y-wheel breaking and in order to obviate any such -unfortunate accident a certain amount of elasticity is given to the' connection between the two parts of the ily-wheel by interposing shock-.absorbing springs, 41, between 4the nuts, 42, and the connected flanges of the fly-wheel parts.

For the purpose of promoting the smooth and eiiicient working of the improved hammer it is found desirable to introduce some elucient means of lubrication and this may be effected by forming in the body of the hammer above the casing an oil reservoir, 43, adapted to be closed by a filling plug, 44, and having therein a' wick,'45, the end of which passes through on orifice into the interior of the casin so that such end will be wiped by the ba l during each revolution of the flywheel so that the ball will thus carry away in its revolution a certain amount of 'oil which will effect an automatic and continuous lubrication of the cylindrical cavity and of the unch or mandril. Y

e operation of the vdevice is similar to that of the apparatus described with reference to Figures 1 to 4 and in both cases the' cam is ixed in the body of the hammer and notv adjustable as it has been found in practice that in hammers of small dimensions the position of the cam exercises only a secondary inliuence upon the direction of the blows and that in practice a fixed cam is capable of producing the same-effect as a movableram.

A rapid movement` of rotation may be given to the fly-wheel by any suitable means and under the influence of centrifugal force the impact member moves outwards away pact member comprises a ball it may be formed as a rolling member generally, the advantage-of such rolling member being that the component tangential to the directlon of impact will be considerably reduced in consequence of the rolling of the memberas compared withthose cases in which the blow is not accompanied by arolling movement.

Moreover, it will be `further understood that the 'device may be employed with more than one such rolling impact member and the arrangement ofthe tool-carrying punch or mandril may be varied according to the purpose for which the hammer is required.

` It is to be further understood that the foregoing details of construction are given by way of illustration only and I may modify the form and construction of the various members or of the driving, guiding, or fixing arrangements which place such members into operative relationship with one another or secure them :to the casings.

Having now described my invention, what I claim as new and desire to secure by Letters Patent is: Y

A centrifugal hammer, comprising a rotatable retaining member having a cylindrical socket, the axis of which is radiall disposedl with respect tothe axis of rotatlon, a cam track surrounding said retaining member, a spherical ball freely and radially movable in said socket and directed against said track by centrifugal force, and an anvil in the path of said ball, said cam track having a portion adapted to cam said ball inwardly of said socket and also having an abrupt change lao 

